This invention relates to a personal cooling jacket which utilizes cold carbon dioxide gas to provide convection cooling. Cooling by convection is maximized, while cooling by conduction, although it occurs to some extent, is relatively less important.
There are many situations in which it is desirable to provide cooling to a worker or other person. However, it is often not economical or practical to cool the environment. For example, although it would be desirable to provide cooling to such people as fire fighters and workers in blast furnaces, steel mills, and other hot areas, it is not practical to cool the working environment. In these instances it is advantageous to use personal cooling, i.e., cooling of the individual rather than the environment.
One way of achieving personal cooling is described in the publication entitled "Personal Cooling With Dry Ice," published in the March, 1974 issue of American Industrial Hygiene Association Journal. This publication describes a method of personal cooling by conduction in which blocks of dry ice are held in pockets of a vest. The vest is worn over bare skin, and the cold dry ice cools the wearer by conduction. Insulation is provided between the dry ice and the skin for protection. The publication describes the use of the vest with and without an outer jacket worn over the vest.
Conduction cooling with dry ice is not entirely satisfactory. Such conduction cooling does not provide uniform cooling, and the areas of the body which are directly adjacent the dry ice will be much colder than remote areas. The body tends to counteract excessive cooling, e.g., by causing shivering which will raise the body heat.